Rémy Oudompheng
|
0184b445c0
|
strconv: implement Ryū-like algorithm for fixed precision ftoa
This patch implements a simplified version of Ulf Adams,
"Ryū: Fast Float-to-String Conversion" (doi:10.1145/3192366.3192369)
for formatting floating-point numbers with a fixed number of decimal
digits.
It uses the same principles but does not need to handle
the complex task of finding a shortest representation.
This allows to handle a few more cases than Grisu3, notably
formatting with up to 18 significant digits.
name old time/op new time/op delta
AppendFloat/32Fixed8Hard-4 72.0ns ± 2% 56.0ns ± 2% -22.28% (p=0.000 n=10+10)
AppendFloat/32Fixed9Hard-4 74.8ns ± 0% 64.2ns ± 2% -14.16% (p=0.000 n=8+10)
AppendFloat/64Fixed1-4 60.4ns ± 1% 54.2ns ± 1% -10.31% (p=0.000 n=10+9)
AppendFloat/64Fixed2-4 66.3ns ± 1% 53.3ns ± 1% -19.54% (p=0.000 n=10+9)
AppendFloat/64Fixed3-4 61.0ns ± 1% 55.0ns ± 2% -9.80% (p=0.000 n=9+10)
AppendFloat/64Fixed4-4 66.9ns ± 0% 52.0ns ± 2% -22.20% (p=0.000 n=8+10)
AppendFloat/64Fixed12-4 95.5ns ± 1% 76.2ns ± 3% -20.19% (p=0.000 n=10+9)
AppendFloat/64Fixed16-4 1.62µs ± 0% 0.07µs ± 2% -95.69% (p=0.000 n=10+10)
AppendFloat/64Fixed12Hard-4 1.27µs ± 1% 0.07µs ± 1% -94.83% (p=0.000 n=9+9)
AppendFloat/64Fixed17Hard-4 3.68µs ± 1% 0.08µs ± 2% -97.86% (p=0.000 n=10+9)
AppendFloat/64Fixed18Hard-4 3.67µs ± 0% 3.72µs ± 1% +1.44% (p=0.000 n=9+10)
Updates #15672
Change-Id: I160963e141dd48287ad8cf57bcc3c686277788e8
Reviewed-on: https://go-review.googlesource.com/c/go/+/170079
Reviewed-by: Emmanuel Odeke <emmanuel@orijtech.com>
Trust: Emmanuel Odeke <emmanuel@orijtech.com>
Trust: Nigel Tao <nigeltao@golang.org>
Trust: Robert Griesemer <gri@golang.org>
Run-TryBot: Emmanuel Odeke <emmanuel@orijtech.com>
TryBot-Result: Go Bot <gobot@golang.org>
|
2021-04-15 08:44:21 +00:00 |
Robert Griesemer
|
1d31f9b1e0
|
strconv: implement parseFloatPrefix returning no. of bytes consumed
parseFloatPrefix will make it easier to implement ParseComplex.
Verified that there's no relevant performance impact:
Benchmarks run on a "quiet" MacBook Pro, 3.3GHz Dual-Core Intel Core i7,
with 16GB 2133MHz LPDDR3 RAM running macOS 10.15.4.
name old time/op new time/op delta
Atof64Decimal-4 38.2ns ± 4% 38.4ns ± 3% ~ (p=0.802 n=5+5)
Atof64Float-4 41.1ns ± 3% 43.0ns ± 1% +4.77% (p=0.008 n=5+5)
Atof64FloatExp-4 71.9ns ± 3% 70.1ns ± 1% ~ (p=0.063 n=5+5)
Atof64Big-4 124ns ± 5% 119ns ± 0% ~ (p=0.143 n=5+4)
Atof64RandomBits-4 57.2ns ± 1% 55.7ns ± 2% -2.66% (p=0.016 n=4+5)
Atof64RandomFloats-4 56.8ns ± 1% 56.9ns ± 4% ~ (p=0.556 n=4+5)
Atof32Decimal-4 35.4ns ± 5% 35.9ns ± 0% ~ (p=0.127 n=5+5)
Atof32Float-4 39.6ns ± 7% 40.3ns ± 1% ~ (p=0.135 n=5+5)
Atof32FloatExp-4 73.7ns ± 7% 71.9ns ± 0% ~ (p=0.175 n=5+4)
Atof32Random-4 103ns ± 6% 98ns ± 2% -5.03% (p=0.008 n=5+5)
Updates #36771.
Change-Id: I8ff66b582ae8b468d89c9ffc35c569c735cf0341
Reviewed-on: https://go-review.googlesource.com/c/go/+/230737
Reviewed-by: Ian Lance Taylor <iant@golang.org>
|
2020-04-30 03:50:03 +00:00 |
Russ Cox